More than two dozen Afghans were killed and dozens more wounded Wednesday in two insurgent attacks in eastern Afghanistan, including an attack in Khost province that also killed three coalition soldiers.

In Khost, a suicide bomber attacked an Afghan-U.S. military convoy, killing two policemen and 14 civilians and wounding 35 others, said Baryalai Rawan, a spokesman for the provincial governor. The U.S. Embassy in Kabul said three coalition soldiers also had been killed in the attack, along with their Afghan interpreter. The statement didn’t identify the soldiers’ nationalities, but most coalition troops in Khost are American.

The attack was the deadliest in a spate of recent violence that contrasts sharply with recent positive statements by coalition officials about the progress of the war in Afghanistan. Earlier this week, the outgoing senior coalition spokesman, German Brig. Gen. Carsten Jacobson, claimed that “the Taliban’s stated spring offensive has so far been a failure.”

Earlier in the day, in Logar province, south of Kabul, a roadside bomb hit a tractor carrying 10 civilians in the Baraki Barak district, killing four children, two women and two men, said Ghulam Sakhi, Logar’s police chief.

Afghan President Hamid Karzai condemned the Khost attack, which follows a series of attacks in the past two days in southern Afghanistan that killed two dozen civilians, police officers, insurgents and coalition soldiers.

Khost province, which borders Pakistan, is one of the most volatile areas of Afghanistan. A truck bomb attack by insurgents June 1 on a U.S. base there killed two Americans and wounded about three dozen troops, according to U.S. military officials.

The attacker in Wednesday’s incident in Khost, who was on foot, set off his explosives at midday in a market near the well-known White Mosque in Khost city, Rawan said.

“The area where the attack took place is a very crowded area where there are a lot of civilians,” Rawan said. He said two women and a child were among the dead, as well as two police officers.

The director of public health for Khost province, Dr. Amir Badshah, said 12 bodies had been taken to government hospitals in the area, including those of three police officers. “The rest are civilians,” Badshah said, and included a child.

Badshah said 17 civilians – including two women and a child – had been admitted for treatment, and four were in critical condition. “The number of casualties may increase,” he said.

Lt. Col. Jimmie Cummings, a coalition spokesman, said insurgents reportedly had attacked a security checkpoint and that a coalition mounted patrol had responded to the incident and secured the area.

The Khost police chief, Brig. Gen. Sardar Mohammad Zazai, told McClatchy that a single suicide bomber had targeted a U.S. convoy that was driving through the city.

“Normally (the Americans) set up checkpoints in different areas, but in this case the convoy was on patrol and passing by,” Zazai said.